Substrate processing apparatus and method and a manufacturing method of a thin film semiconductor device

ABSTRACT

A substrate processing apparatus includes a plurality of evacuable treatment chambers connected to one another via an evacuable common chamber, and the common chamber is provided with means for transporting a substrate between each treatment chamber. More specifically, a substrate processing apparatus includes a plurality of evacuable treatment chambers, at least one of said treatment chambers having a film formation function through a vapor phase reaction therein, at least one of said treatment chambers having an annealing function with light irradiation and at least one of said treatment chambers having a heating function therein. The apparatus also has a common chamber through which said plurality of evacuable treatment chambers are connected to one another, and a transportation means provided in said common chamber for transporting a substrate between each treatment chamber.

This application is a Continuation of Ser. No. 08/321,321, filed Oct.11, 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for forming asemiconductor device on or within a surface of a substrate. Inparticular, the present invention relates to an apparatus which iscapable of processing a substrate sequentially without exposing to theoutside air. Also, the present invention relates to a multi-purposesubstrate processing apparatus which can be used to manufacture a thinfilm integrated circuit.

2. Prior Art

Integrated circuits which use semiconductor substrates or glasssubstrates are known. The former is known as IC or LSI and the latter isknown, for example, as a liquid crystal device of an active matrix type.It is necessary to carry out each process successively in order tomanufacture the integrated circuits. For example, when manufacturing aninsulated gate field effect semiconductor device, it is desired that achannel forming semiconductor region and a gate insulating layercontacting thereto be formed sequentially without exposing to the air.

Also, there was a manufacturing system for producing a semiconductordevice which utilizes an amorphous silicon or a single crystallinesilicon, however, there was no manufacturing system which is suitablefor manufacturing a semiconductor device which utilizes apolycrystalline silicon.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide a substrateprocessing apparatus which can be used multi-purposely, morespecifically, which is capable of performing each step of manufacturinga semiconductor device successively in one apparatus.

It is another object of the present invention to provide a method and amanufacturing apparatus for manufacturing a polycrystallinesemiconductor device successively, for example, for forming a siliconfilm and performing a crystallization thereof in different chamberssuccessively.

In accordance with a first accept of the present invention, a substrateprocessing apparatus includes a plurality of evacuable treatmentchambers (i.e. chambers capable of being evacuated) connected to oneanother via an evacuable common chamber, and the common chamber isprovided with means for transporting a substrate between each treatmentchamber.

More specifically, a substrate processing apparatus includes a pluralityof evacuable treatment chambers, at least one of said treatment chambershaving a film formation function through a vapor phase reaction therein,at least one of said treatment chambers having an annealing functionwith light irradiation and at least one of said treatment chambershaving a heating function therein. The apparatus also has a commonchamber through which said plurality of evacuable treatment chambers areconnected to one another, and a transportation means provided in saidcommon chamber for transporting a substrate between each treatmentchamber.

Also, a method for operating the substrate processing apparatus inaccordance with the first aspect of the present invention ischaracterized by the steps of transferring a substrate between atreatment chamber and a common chamber while the pressure in bothchambers is maintained equal with each other.

In accordance with a second aspect of the present invention, a methodfor manufacturing a semiconductor device which utilizes apolycrystalline silicon comprises the steps of forming a non-singlecrystalline silicon film in a first chamber through LPCVD usingpolysilane such as disilane and performing another step, for example, aformation of an insulating film adjacent to the silicon film or acrystallization thereof, in a second chamber successively withoutexposing a substrate to the outside air. The inventors found that when asilicon film is formed through a glow discharge plasma CVD, the qualityof the silicon film tends to be hindered because hydrogen effuses fromthe silicon film when it is crystallized. Accordingly, even if amulti-chamber system was used, the quality of the polycrystallinesilicon semiconductor device could not be so improved. Based on therecognition of this problem, the silicon film is formed through LPCVDusing a polysilane. Moreover, quality of an interface between thesilicon film and its adjacent insulating film can be improved by formingthe silicon film and the insulating film adjacent thereto successivelywithout exposing them to the air.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the invention will be described inpreferred embodiments of the invention with reference to the attacheddrawings in which:

FIG. 1 shows a schematic diagram of a substrate processing apparatus ofthe present invention;

FIGS. 2A-2F show a manufacturing process of a semiconductor device inaccordance with Example 2 of the invention;

FIGS. 3A-3F show a manufacturing process of a semiconductor device inaccordance with Example 3 of the invention; and

FIG. 4 shows an example of a specification of each chamber of theapparatus shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

A first preferred embodiment in accordance with the first aspect of theinvention will be described with reference to FIG. 1. In FIG. 1, thereference numeral 107 shows a common chamber which in turn is asubstrate transfer chamber. Among treatment chambers 101-106, thechambers 101 and 102 are auxiliary chambers through which a substrate isloaded and unloaded. The chamber 103 is, for example, a sputteringapparatus for forming an insulating film. The chamber 104 is, forexample, a plasma CVD apparatus for forming an amorphous silicon. Thechamber 105 is, for example, a heating furnace for forming a thermaloxide film. The chamber 106 is, for example, an annealing furnace forperforming an annealing with light irradiation. The kinds of treatmentscarried out in each treatment chamber can be determined arbitrarily.Examples of treatments are plasma CVD, LPCVD (low pressure thermal CVD),photo CVD, microwave CVD, heating furnace, annealing furnace with lightirradiation, sputtering, plasma annealing, isotropic or anisotropicetching, etc. More specific examples of the first preferred embodimentwill be described below.

EXAMPLE 1

Referring to FIG. 1, the chambers 101 and 102 are used to load andunload substrates. These chambers have a function of holding a cassetteto which a plurality of substrates are placed. Obviously, these chambersare provided with means for introducing therein necessary gases such asan inert gas or a cleaning gas and an evacuation means. (not shown) Forexample, the substrate is 4×4 inches square, 5×5 inches square or 5×6inches. The chambers 103, 105 and 106 are used to form films,respectively. The chamber 104 is a temperature controlling chamber whichhas a function of preheating a substrate to a predetermined temperaturebefore a plasma CVD in another chamber. FIG. 4 shows a specification ofeach treatment chamber. The chamber 107 is a substrate transfer chamberin which a robot arm 108 is provided for moving a substrate between eachtreatment chamber. The robot arm has a function of taking out asubstrate 109 from the auxiliary chamber 101 or 102 and transferring itto a desired treatment chamber. The substrate transfer chamber isprovided with an evacuating means to evacuate it to a desired vacuum.(not shown)

The transfer of a substrate between each chamber is carried in thefollowing manner. Provided that a substrate initially held in theauxiliary chamber is moved into the treatment chambers 103 and 104 andtreated therein sequentially, following which it is transferred into theauxiliary chamber 102, the substrate conveying process comprises thefollowing sequential steps of:

(1) while evacuating the auxiliary chamber 101 and the transfer chamber107 to a same degree of vacuum, opening a gate valve 110 andtransferring the substrate 109 to the transfer chamber 107 using therobot arm 108, after that the gate valve 110 is closed;

(2) while evacuating the transfer chamber 107 and the treatment chamber103 to a same degree of vacuum, opening a gate valve 112 andtransferring the substrate 109 into the treatment chamber 103 followingwhich the gate valve 112 is closed;

(3) performing a predetermined treatment on the substrate in thetreatment chamber 103;

(4) after evacuating the treatment chamber 103 to a same degree as inthe transfer chamber 107, opening the gate valve 112 and transferringthe substrate 109 into the transfer chamber 107 with a robot armfollowing which the gate valve 112 is closed;

(5) while evacuating the transfer chamber 107 and the treatment chamber104 to a same degree of vacuum, opening a gate valve 113 andtransferring the substrate 109 into the treatment chamber 104 followingwhich the gate valve 113 is closed;

(6) performing a predetermined treatment on the substrate in thetreatment chamber 104;

(7) after evacuating the treatment chamber 104 to a same degree as inthe transfer chamber 107, opening the gate valve 113 and transferringthe substrate with a robot arm following which the gate valve 113 isclosed; and then,

(8) while maintaining the transfer chamber 107 and the auxiliary chamber102 at a same degree of a vacuum, opening a gate valve 111 andtransferring the substrate to the auxiliary chamber 102 with the robotarm 108, and then closing the gate valve 111.

In the above manner, it is possible to perform two or more treatmentssuccessively without exposing the substrate to an outside air.

Substrates held in the cassette in the auxiliary chambers 101 can beprocessed one by one successively by repeating the foregoing steps (1)to (8). A substrate on which the predetermined process has be finishedis automatically put into a cassette placed in the auxiliary chamber102. Also, it is possible to clean the treatment chamber 104 whileperforming a film formation in the chamber 103 or to clean the treatmentchamber 103 while performing a film formation in the chamber 104.Accordingly, it is possible to perform the predetermined process in onechamber and to clean another treatment chamber(s) at the same timewithout stopping the operation of the entire apparatus. NF₃ can be usedas a cleaning gas for plasma cleaning the inside of the chambers.

EXAMPLE 2

This example is directed to a manufacture of a thin film integratedcircuit including at least one thin film transistor. FIGS. 2A-2F show amanufacturing process of the thin film transistor.

Referring again to FIG. 1, the treatment chamber 103 is designed to forman aluminum nitride (aluminum oxinitride) or silicon nitride filmthrough a plasma CVD, the treatment chamber 104 is used to conduct arapid thermal annealing or preheating with an infrared ray for a shortduration, the treatment chamber 105 is designed to form a silicon oxidefilm through a plasma CVD using TEOS (tetraethoxysilane) and thetreatment chamber 106 is designed to form an amorphous silicon filmthrough a plasma CVD as shown in FIG. 2A. These chambers are eachprovided with a gas introducing means and an evacuation means. (notshown)

Initially, a Corning 7059 glass substrate 109 (4×4 inches square, 5×5inches square or 5×6 inches) is placed in the auxiliary chamber 101. Thechamber 101 is evacuated preferably to a same degree of vacuum as in the20 transfer chamber 107 which is maintained at a sufficiently highvacuum. Then, after opening the gate valve 110, the substrate 109 istransferred from the auxiliary chamber 101 to the transfer chamber 107with the robot arm 108. Then, while maintaining the treatment chamber103 at a same vacuum as in the transfer chamber 107, the gate valve 112is opened and 25 the substrate is transferred to the treatment chamber103, following which the gate valve 112 is closed. In the treatmentchamber 103, an aluminum nitride film 202 is formed on the substrate toa thickness of 2000-5000 Å through plasma CVD. Al(C₄H₉)₃ or Al(CH₃)₃ isused as a starting material gas together with a nitrogen gas. It ispossible to add N₂O at a small amount in order to reduce a thermalexpansion stress.

After the formation of the aluminum nitride 202, the treatment chamber103 is again evacuated to the same degree of vacuum as the transferchamber 107, following which the gate valve 112 is opened and thesubstrate 109 is transferred from the treatment chamber 103 into thetransfer chamber 107. In the later steps, the transfer of the substratebetween each treatment chamber and the transfer chamber will be done inthis manner. Also, needless to say, films formed on the substrate 109are transferred together with the substrate when the substrate istransferred between the chambers although it is not specificallymentioned.

The substrate 109 is then transferred into the chamber 104 to perform arapid thermal annealing. The annealing is done in an atmosphere ofnitrogen, ammonium (NH₃) or dinitrogen monoxide (N₂O). The aluminumnitride film 202 is rapidly heated by the annealing and becomestransparent. At the same time, the insulating property and the thermalconductivity of the film can be improved. It is possible to form asilicon nitride film in order to prevent an impurity such as sodium fromdiffusing into a semiconductor film from the glass substrate. Thesilicon nitride film can be formed through plasma CVD at a substratetemperature 350° C., at a pressure of 0.1 Torr, using a mixture gas ofSiH₄ and NH₃.

After the rapid thermal annealing, the substrate is transferred from thechamber 104 to the chamber 105 through the transfer chamber 107 in thesame manner as explained above. In the chamber 105, a silicon oxide film203 is formed to a thickness of 50-2000 Å through a plasma CVD using aTEOS gas mixed with oxygen as a starting material. The processparameters are shown below:

TEOS/O₂ ratio 10/100 sccm RF power 350 W substrate temp. 400° C.pressure 0.25 Torr

It is possible to add a C₂F₆ gas to the starting gas in order to form afilm expressed by a formula SiOF_(x). The silicon oxide film 203 will bean underlying layer for a thin film transistor to be formed later. Also,it is possible to carry out a rapid thermal annealing in the treatmentchamber 104 after the formation of the silicon oxide film 203.

Then, the substrate is transferred into the treatment chamber 106 wherean amorphous silicon film 204 is formed to a thickness of 100-1500 Å,preferably, from 300 to 800 Å through a plasma CVD or LPCVD with thefollowing formation parameters:

SiH₄ 200 sccm RF power 200 W substrate temp. 250° C. pressure 0.1 Torr

The amorphous silicon film may be formed using Si₂H₆ and Si₃H₈ in aLPCVD (low pressure thermal CVD). An example of a formation condition inthe case of using LPCVD is shown below.

Si₂H₆ 100-500 sccm He 500 sccm formation temp. 400-500° C. pressure0.1-1 Torr

Further, the substrate is transferred to the treatment chamber 105 wherea silicon oxide film 212 is formed to a thickness of 500-1500 Å througha plasma CVD using TEOS as a starting material. This film functions as ablocking layer for the silicon film. The formation conditions of thesilicon oxide film 212 is as follows:

TEOS/O₂ 10/1000 sccm RF power 300 W substrate temp. 350° C. pressure0.25 Torr

As a result, an aluminum nitride or silicon nitride blocking film 202, asilicon oxide film 203, a silicon semiconductor film 204 and a blockingfilm 212 can be laminated on a substrate 109 successively as shown inFIG. 2A. Since each treatment chamber is divided from the transferchamber 107 by the gate valve, a mutual contamination with impuritiesbetween each chamber can be avoided. As a result, it is possible toreduce a concentration of C, N and O in the silicon film to at least5×10¹⁸ atoms/cm³ or less, respectively.

Next, the substrate having the above laminated structure thereon istaken out from the auxiliary chamber 102 in order to pattern the siliconsemiconductor film into an island form as shown in FIG. 2B. Then, asilicon oxide film 205 is formed on the patterned silicon film 204 to athickness of 200-150 Å, preferably 500-1000 Å to form a gate insulatingfilm. The silicon oxide film 205 is formed using TEOS gas and oxygen gasat a volume ratio 1:1 to 1:3, at a pressure of 0.05-0.5 Torr, and at anRF power of 100−2 50 W. This step may be carried out in the treatmentchamber 105. In this case, it is preferable to perform a rapid thermalannealing with IR light in N₂O atmosphere in the annealing chamber 104after the formation of the silicon oxide film 205. Alternatively, thesilicon oxide film can be formed through a LPCVD or an atmosphericpressure CVD using TEOS and ozone gas at 350-600° C. substratetemperature, preferably, 400-550° C.

After the formation of the silicon oxide film 205, the silicon oxidefilm is annealed in oxygen or ozone atmosphere at 400-600° C. for 30-60minutes. The interface states in the silicon oxide film 205 and thesilicon film 204 can be greatly reduced by the annealing step.

Then, as shown in FIG. 2B, a KrF excimer laser 213 (wavelength 248 nm or308 nm, pulse width 20 nsec) is irradiated in order to crystallize thesilicon film 204. The energy density of the laser is 200-400 mJ/cm²,preferably, 250-300 mJ/cm². Also, the substrate is heated at 300-500° C.during the laser irradiation. When observing the silicon film 204through a Raman scattering spectrometry, a relatively broad peak isobserved not at the 521 cm⁻¹ of a single crystal silicon but at around515 cm⁻¹, which means that the silicon film 204 is crystalline, forexample polycrystalline. The crystallization step may be carried out bya heat annealing. Thereafter, the substrate is annealed at 350° C. for 2hours in a hydrogen atmosphere.

Next, an aluminum film is formed to a thickness of 2000 Å to 1 μm by anelectron beam evaporation method, following which the aluminum film ispatterned to be a gate electrode 206. It is possible to add scandium(Sc) to the aluminum at 0.15-0.2 weight %. Then, the aluminum gateelectrode 206 is subjected to an anodic oxidation in an electrolyte. Theelectrolyte is ethylene glycol mixed with a tartaric acid at 1-3%. ThepH of the electrolyte is set about 7. Also, the aluminum gate electrodefunctions as an anode while platinum is used as a cathode. At a firststage of the anodic oxidation, a voltage is increased to 220 V whilemaintaining a current constant, then this condition is maintained for 1hour. The voltage is increased at a rate of 2-5 V/minute. Thus, ananodic oxide film 209 is formed to a thickness of 1500-3500 Å, forexample, 2000 Å as shown in FIG. 2C.

When a high temperature treatment is necessary, it is desirable to usetantalum instead of aluminum.

After the formation of the anodic oxide film 209, an impurity(phosphorous) is added into a portion of the silicon film 204 by an iondoping method (also called as a plasma doping method) with the gateelectrode portion used as a mask in a self-aligning manner. Phosphine(PH₃) is used as a dopant gas. The dose amount is 1-4×10¹⁵ atoms/cm².

Further, a KrF excimer laser 216 (wavelength 248 nm or 308 nm, pulsewidth 20 nsec) is irradiated as shown in FIG. 2D in order to activatethe introduced impurity and form impurity regions 208 and 209. At thesame time, a damage caused by the introduction of the impurity is curedby the laser irradiation. The energy density of the laser beam is150-400 mJ/cm², preferably, 200-250 mJ/cm². The sheet resistance of theimpurity regions 208 and 209 is in the range of 200-800 Ω/square. Inplace of using a laser, a flush lump may be used in order to heat asample to 1000-1200° C. in a short time. This step is so called RTP(rapid thermal process). The temperature is observed by monitoring atemperature of a silicon.

A silicon oxide film 210 is then formed on the entire surface as aninterlayer insulator. The deposition is carried out in the treatmentchamber 105 using a mixture of TEOS and oxygen as a starting gas. TheCVD may be any one of plasma CVD, low pressure CVD or atmosphericpressure CVD. The thickness of the silicon oxide film is 0.3 μm to 1 μm,for example, 0. 3 μm (3000 Å). The substrate temperature during thedeposition is in the range of 250-450° C., for example, 350° C. Thesilicon oxide film is mechanically polished to obtain a leveled surface.This step may be replaced by an isotropic dry etching in a chamberprovided in an apparatus of FIG. 1. Further, an ITO film is formed bysputtering and patterned to form a pixel electrode 211 as shown in FIG.2E.

The interlayer insulator 210 is etched as shown in FIG. 2F in order toform contact holes through which wirings 214 and 215 can reach theimpurity regions (source and drain regions). The wiring 215 is connectedto the pixel electrode 211. Also, the material of the wirings ischromium or titanium nitride, for example. As shown in FIG. 2F, thewirings contact both of the top surface and side surface of the impurityregions. This configuration is called as a “top-side contact”. Theportion of the contact hole which extends beyond the silicon islandoccupies 30-70% of the entire area of the contact hole.

The use of the aluminum nitride or silicon nitride film 202 isparticularly advantageous for obtaining the top-side contact because itprevents the substrate surface from being etched or damaged duringforming the contact holes. Namely, even if the underlying silicon oxidefilm 203 is unintentionally etched off during the formation of thecontact holes, the aluminum nitride or silicon nitride film 202functions as an etching stopper.

Also, the top-side contact is advantageous because the size of thecontact holes may be made relatively larger. In the prior art, the sizeof the contact hole should be smaller than the size of the source/drainregion. However, in the top-side contact structure, the contact hole maybe larger than the silicon island. Accordingly, the formation of thecontact holes can be eased.

Finally, the entire structure is annealed in hydrogen at 300-400° C. for1 to 2 hours in order to hydrogenate the silicon. Although not shown inthe drawings, a plurality of TFTs are formed on the same substrate inthe form of a matrix at the same time. Also, a peripheral circuitconstituted by TFTs may be formed on the same substrate at through thesame process. Thus, a circuit substrate for a monolithic type activematrix liquid crystal device is formed.

The substrate processing apparatus of the present invention iscontrolled by a microcomputer in order to obtain a higher productionyield and a cost performance.

EXAMPLE 3

The third example of the present invention in accordance with a secondaspect of the present invention will be described. The same apparatusshown in FIG. 1 is used in this example. However, the chamber 106 isused to perform LPCVD to form an amorphous silicon and the chamber 102is used to perform LPCVD to form a p-doped polysilicon therein in thisexample.

Initially, a crystal glass substrate 109 which has a high heatresistivity, for example, N-0 glass manufactured by Nippon ElectricGlass Co. is introduced into the substrate processing apparatus from theload-unload chamber 101. The transfer of the substrate is done in thesame way as in the first example of the invention. The substrate 109 istransferred to the transfer chamber 107 and then introduced into theplasma CVD chamber 103 by the robot arm 108. In the chamber 103, asilicon nitride film 202 is formed through plasma CVD as shown in FIG.3A. A mixture gas of SiH₄ and NH₃ is used as a starting gas. Also, thesubstrate temperature is 350° C. and the pressure inside the chamber is0.1 torr. The silicon nitride film 202 will prevent a diffusion ofalkali metals such as lithium contained in the glass substrate. In placeof silicon nitride, it is possible to form silicon oxide added with ahalogen element such as fluorine in order to block movable ions.

Then, the substrate is transferred into the chamber 105 via the transferchamber 107 to form a silicon oxide film 203. The silicon oxide film 203is formed to a thickness of 50-2000 Å by plasma CVD using TEOS andoxygen as a starting material with the following process condition:

TEOS/O₂ 10/100 sccm RF power 350 W substrate temp. 400° C. pressure 0.25Torr

Also, C₂F₆ may be added to the above starting material to form a filmexpressed by a chemical formula SiOF_(x). The silicon oxide film 203functions as a base film for a TFT to be formed thereon.

Then, the substrate is transferred to the chamber 106 in order to forman amorphous silicon film 204 through LPCVD with the following processcondition:

Si₂H₆ 100 sccm He 200 sccm Heating Temp. 400° C.-570° C., Preferably,500-570° C. Pressure 0.3 Torr growth rate 50-500 Å/minute

The use of a polysilane such as disilane is advantageous for obtaining apolycrystalline silicon film with an excellent property having anaverage rain size in the range of 250-8000 Å after a heatcrystallization.

On the amorphous silicon film 204, a blocking film 212 comprisingsilicon oxide is formed in the chamber 105 by a plasma CVD using TEOSand oxygen as a starting material. Subsequently, the substrate isreturned to the load-unload chamber 101 and taken out to the outside inorder to pattern the amorphous silicon 204 together with the blockingfilm 212 into an island form and crystallize it. Since the patterningstep and the crystallization step are not performed in a reducedpressure and take much longer time as compared with other steps, it ispreferable that these steps are carried out with a different system inorder to increase the operation rate of the apparatus. Accordingly, theblocking film 212 prevents the surface of the amorphous silicon film 204form being contaminated by the air.

The patterning of the amorphous silicon film 204 is carried out by aknown photolithography into a predetermined island pattern.

The heat crystallization is done at 550-600° C. in a nitrogen atmospherefor 8-56 hours. At this relatively low temperature, it is possible toobtain polycrystalline film with a large grain size as said above.

Then, a thermal annealing is performed at a higher temperature. Thetemperature is as high as the N-0 glass substrate can endure it, forexample, 800-850° C. Thereby, the crystallinity within each crystalgrain can be further improved. Also, this step may be carried out in anoxidizing atmosphere, for example, dry oxygen in order to form a thermaloxidation film. When using the thermal oxidation film as a gateinsulating film, the appropriate thickness of the film is 500-2000 Å.

After the heat crystallization, the substrate is introduced again intothe apparatus of the present invention from the auxiliary chamber 101.Depending upon necessity, the substrate is further transferred to thechamber 105, in which a silicon oxide film 205 is to be formed through aRF plasma CVD. Of course, the blocking film is removed by etching beforethe formation of the silicon oxide film 205 in an appropriate one of thechambers of the apparatus in order to expose a clean surface of thesilicon film 204. The plasma CVD is carried out using TEOS and oxygen asa starting material and the substrate temperature at 300-450° C. Thepressure ratio of the TEOS and oxygen is 1:1-1:3, and the entirepressure is 0.05-0.5 Torr. Also, the RF power is 100-250 W. Instead ofplasma CVD, it is possible to form the silicon oxide film through LPCVDor atmospheric pressure CVD using TEOS mixed with ozone gas at asubstrate temperature 350-600° C., preferably, 400-550° C.

Thus, as shown in FIG. 3B, a blocking film 202 made of silicon nitride,silicon oxide film 203, a crystalline silicon film 204 patterned into anisland form, and silicon oxide film 205. It is possible to maintain theconcentration of carbon, nitrogen or oxygen at 5×10¹⁸ atoms/cm³ or lessbecause of the use of the apparatus of the present invention.

It is advantageous to perform a rapid thermal annealing with an IR lightin N₂O atmosphere in the chamber 104 after the formation of the siliconoxide film 205 in order to reduce interface states between the siliconoxide film 205 and the silicon film 204.

Then, transferring the substrate into the chamber 102, a phosphorousdoped polysilicon film is formed through LPCVD to a thickness of1000-4000 Å to form a gate electrode 217 as shown in FIG. 3C.

The steps starting from the formation of the underlying film and to theformation of the material for the gate electrode are carried outsubstantially without exposing the surface of each layer to the air.Thereby, it is possible to improve the each interface quality which is amain factor for determining the device property.

After the formation of the phosphorous doped polysilicon film, thesubstrate is taken out from the load-unload chamber 101. The next stepswill be carried out outside of the apparatus of FIG. 1.

The phosphorous doped polysilicon film is patterned into a gateelectrode 217 by drying etching. (FIG. 3C)

Then, the silicon island 204 is selectively doped with a dopant impurity(phosphorous) in a self-aligning manner using the gate electrode 217 inorder to form source and drain regions 208 and 209. The doping iscarried out by ion doping. Phosphine (PH₃) is used as a dopant gas.Also, the dose amount is 1-4×10¹⁵/cm².

Subsequently, the substrate is heated at 600° C. for 12 hours in anitrogen atmosphere in order to activate the dopant, following which itis heat annealed in a hydrogen atmosphere at 400° C. for 1 hour in orderto perform hydrogenation of the semiconductor film and reduce a defectlevel density.

A silicon oxide film 210 is then formed on the entire surface as aninterlayer insulator. The deposition is carried out in the treatmentchamber 105 using a mixture of TEOS and oxygen as a starting gas. TheCVD may be any one of plasma CVD, low pressure CVD or atmosphericpressure CVD. Alternatively, the silicon oxide film 210 may be formed ina different apparatus from the apparatus of FIG. 1. The thickness of thesilicon oxide film is 0.3 μm to 1 μm, for example, 0.3 μm (3000 Å). Thesubstrate temperature is in the range of 250-450° C., for example, 350°C. The silicon oxide film is mechanically polished to obtain a leveledsurface. This step may be replaced by an isotropic dry etching in achamber provided in an apparatus of FIG. 1. Further, an ITO film isformed by sputtering and patterned to form a pixel electrode 211 asshown in FIG. 3E.

The interlayer insulator is etched as shown in FIG. 3F in order to formcontact holes through which wirings 214 and 215 can reach the impurityregions (source and drain regions). The wiring 215 is connected to thepixel electrode 211. Also, the material of the wirings is chromium ortitanium nitride, for example. As shown in FIG. 3E, the wirings contactboth of the top surface and side surface of the impurity regions, i.e.top-side contact.

Finally, the entire structure is annealed in hydrogen at 300-400° C. for1 to 2 hours. As a result, the silicon is hydrogenated. Although notshown in the drawings, a plurality of TFTs are formed on the samesubstrate in the form of a matrix at the same time. Also, a peripheralcircuit constituted by TFTs may be formed on the same substrate. Thus, acircuit substrate for a monolithic type active matrix liquid crystaldevice is formed.

While the present invention is described with reference to the preferredembodiments, the present invention should not be limited to theseparticular examples but limited only to the appended claims. Manymodifications may be made without departing the scope of the invention.

For example, various kinds of substrates may be processed in theapparatus of the present invention, for example, glass substrate,semiconductor substrate such as silicon substrate, or other insulatingmaterials including a semiconductive or conductive substrates having aninsulating surface thereon. For example, a glass substrate is suitablewhen forming an electro-optical device such as an active matrix liquidcrystal device or an image sensor. Also, when using quartz as asubstrate, the silicon nitride film 202 and silicon oxide film 203 maybe omitted. Further, it is possible to raise the temperature of thethermal annealing after heat crystallization or heat oxidation to about1000° C. when using a quartz substrate. Accordingly, it is possible toobtain a crystalline silicon film having an improved crystallinity.

Also, the TFT formed in the present invention may be a bottom gate typeTFT.

What is claimed is:
 1. A method of manufacturing a semiconductor devicecomprising the steps of: forming a first insulating film comprisingsilicon oxide over a substrate in a multi-chamber apparatus having aplurality of film formation chambers; forming a semiconductor filmcomprising amorphous silicon on said first insulating film in saidmulti-chamber apparatus; forming a second insulating film comprisingsilicon oxide on said semiconductor film in said multi-chamber apparatuswherein said first insulating film, said semiconductor film and saidsecond insulating film are successively formed without taking saidsubstrate out of said multi-chamber apparatus; taking said substrate outof the multi-chamber apparatus after the formation of said secondinsulating film; crystallizing said semiconductor film outside saidmulti-chamber apparatus with said second insulating film formed on saidsemiconductor film; patterning the crystallized semiconductor film toform a semiconductor island; and forming a gate insulating film on saidsemiconductor island.
 2. A method of manufacturing a semiconductordevice comprising the steps of: forming a first insulating filmcomprising silicon oxide over a substrate in a multi-chamber apparatushaving a plurality of film formation chambers; forming a semiconductorfilm comprising amorphous silicon on said first insulating film in saidmulti-chamber apparatus; forming a second insulating film comprisingsilicon oxide on said semiconductor film in said multi-chamber apparatuswherein said first insulating film, said semiconductor film and saidsecond insulating film are successively formed without taking saidsubstrate out of said multi-chamber apparatus; taking said substrate outof the multi-chamber apparatus after the formation of said secondinsulating film; crystallizing said semiconductor film outside saidmulti-chamber apparatus with said second insulating film formed on saidsemiconductor film; patterning the crystallized semiconductor film toform a semiconductor island; etching said second insulating film toexpose a surface of the semiconductor island; and forming a gateinsulating film on said semiconductor island.
 3. A method ofmanufacturing a semiconductor device comprising the steps of: forming afirst insulating film comprising silicon oxide over a substrate in amulti-chamber apparatus having a plurality of film formation chambers;forming a semiconductor film comprising amorphous silicon on said firstinsulating film in said multi-chamber apparatus; forming a secondinsulating film comprising silicon oxide on said semiconductor film insaid multi-chamber apparatus wherein said first insulating film, saidsemiconductor film and said second insulating film are successivelyformed without taking said substrate out of said multi-chamberapparatus, taking said substrate out of the multi-chamber apparatusafter the formation of said second insulating film; crystallizing saidsemiconductor film outside said multi-chamber apparatus with said secondinsulating film formed on said semiconductor film; patterning thecrystallized semiconductor film to form a semiconductor island; andforming a gate insulating film on said semiconductor island, whereinsaid semiconductor film is formed in a different chamber from said firstinsulating film and said second insulating film.
 4. A method ofmanufacturing a semiconductor device comprising the steps of: forming afirst insulating film comprising silicon oxide over a substrate in amulti-chamber apparatus having a plurality of film formation chambers;forming a semiconductor film comprising amorphous silicon on said firstinsulating film in said multi-chamber apparatus; forming a secondinsulating film comprising silicon oxide on said semiconductor film insaid multi-chamber apparatus wherein said first insulating film, saidsemiconductor film and said second insulating film are successivelyformed without taking said substrate out of said multi-chamberapparatus; taking said substrate out of the multi-chamber apparatusafter the formation of said second insulating film; crystallizing saidsemiconductor film outside said multi-chamber apparatus with said secondinsulating film formed on said semiconductor film; patterning thecrystallized semiconductor film to form a semiconductor island; etchingsaid second insulating film to expose a surface of the semiconductorisland; and forming a gate insulating film on said semiconductor island,wherein said semiconductor film is formed in a different chamber fromsaid first insulating film and said second insulating film.
 5. A methodof manufacturing a semiconductor device comprising the steps of: forminga first insulating film comprising silicon oxide over a substrate in amulti-chamber apparatus having a plurality of film formation chambers;forming a semiconductor film comprising amorphous silicon on said firstinsulating film in said multi-chamber apparatus; forming a secondinsulating film comprising silicon oxide on said semiconductor film insaid multi-chamber apparatus wherein said first insulating film, saidsemiconductor film and said second insulating film are successivelyformed without taking said substrate out of said multi-chamberapparatus; taking said substrate out of the multi-chamber apparatusafter the formation of said second insulating film; crystallizing saidsemiconductor film outside said multi-chamber apparatus with said secondinsulating film formed on said semiconductor film; patterning thecrystallized semiconductor film to form a semiconductor island; andforming a gate insulating film on said semiconductor island, whereinsaid semiconductor film is formed in a first chamber of saidmulti-chamber apparatus and said first and second insulating films areformed in a second chamber of said multi-chamber apparatus.
 6. A methodof manufacturing a semiconductor device comprising the steps of: forminga first insulating film comprising silicon oxide over a substrate in amulti-chamber apparatus having a plurality of film formation chambers;forming a semiconductor film comprising amorphous silicon on said firstinsulating film in said multi-chamber apparatus; forming a secondinsulating film comprising silicon oxide on said semiconductor film insaid multi-chamber apparatus wherein said first insulating film, saidsemiconductor film and said second insulating film are successivelyformed without taking said substrate out of said multi-chamberapparatus; taking said substrate out of the multi-chamber apparatusafter the formation of said second insulating film; crystallizing saidsemiconductor film outside said multi-chamber apparatus with said secondinsulating film formed on said semiconductor film; patterning thecrystallized semiconductor film to form a semiconductor island; etchingsaid second insulating film to expose a surface of the semiconductorisland; and forming a gate insulating film on said semiconductor island,wherein said semiconductor film is formed in a first chamber of saidmulti-chamber apparatus and said first and second insulating films areformed in a second chamber of said multi-chamber apparatus.
 7. A methodof manufacturing a semiconductor device comprising the steps of: forminga first insulating film comprising silicon nitride over a substrate in amulti-chamber apparatus having a plurality of film formation chambers;forming a second insulating film comprising silicon oxide in saidmulti-chamber apparatus; forming a semiconductor film comprisingamorphous silicon on said second insulating film in said multi-chamberapparatus; forming a third insulating film comprising silicon oxide onsaid semiconductor film in said multi-chamber apparatus wherein saidfirst insulating film, said second insulating film, said semiconductorfilm and said third insulating film are successively formed withouttaking said substrate out of said multi-chamber apparatus; taking saidsubstrate out of the multi-chamber apparatus after the formation of saidthird insulating film; crystallizing said semiconductor film outsidesaid multi-chamber apparatus with said third insulating film formed onsaid semiconductor film; patterning the crystallized semiconductor filmto form a semiconductor island; and forming a gate insulating film onsaid semiconductor island.
 8. A method of manufacturing a semiconductordevice comprising the steps of: forming a first insulating filmcomprising silicon nitride over a substrate in a multi-chamber apparatushaving a plurality of film formation chambers; forming a secondinsulating film comprising silicon oxide in said multi-chamberapparatus; forming a semiconductor film comprising amorphous silicon onsaid second insulating film in said multi-chamber apparatus; forming athird insulating film comprising silicon oxide on said semiconductorfilm in said multi-chamber apparatus wherein said first insulating film,said second insulating film, said semiconductor film and said thirdinsulating film are successively formed without taking said substrateout of said multi-chamber apparatus; taking said substrate out of themulti-chamber apparatus after the formation of said third insulatingfilm; crystallizing said semiconductor film outside said multi-chamberapparatus with said third insulating film formed on said semiconductorfilm; patterning the crystallized semiconductor film to form asemiconductor island; etching said third insulating film to expose asurface of the semiconductor island; and forming a gate insulating filmon said semiconductor island.
 9. The method according to claim 1 whereinsaid semiconductor film is formed by LPCVD.
 10. The method according toclaim 1 wherein said first insulating film and said second insulatingfilm are formed by PCVD using a raw material gas comprising TEOS. 11.The method according to claim 1 wherein the crystallization of saidsemiconductor film is carried out by heating.
 12. The method accordingto claim 1 wherein said semiconductor device is an active matrix displaydevice.
 13. The method according to claim 2 wherein said semiconductorfilm is formed by LPCVD.
 14. The method according to claim 2 whereinsaid first insulating film and said second insulating film are formed byPCVD using a raw material gas comprising TEOS.
 15. The method accordingto claim 2 wherein the crystallization of said semiconductor film iscarried out by heating.
 16. The method according to claim 2 wherein saidsemiconductor device is an active matrix display device.
 17. The methodaccording to claim 3 wherein said semiconductor film is formed by LPCVD.18. The method according to claim 3 wherein said first insulating filmand said second insulating film are formed by PCVD using a raw materialgas comprising TEOS.
 19. The method according to claim 3 wherein thecrystallization of said semiconductor film is carried out by heating.20. The method according to claim 3 wherein said semiconductor device isan active matrix display device.
 21. The method according to claim 4wherein said semiconductor film is formed by LPCVD.
 22. The methodaccording to claim 4 wherein said first insulating film and said secondinsulating film are formed by PCVD using a raw material gas comprisingTEOS.
 23. The method according to claim 4 wherein the crystallization ofsaid semiconductor film is carried out by heating.
 24. The methodaccording to claim 4 wherein said semiconductor device is an activematrix display device.
 25. The method according to claim 5 wherein saidsemiconductor film is formed by LPCVD.
 26. The method according to claim5 wherein said first insulating film and said second insulating film areformed by PCVD using a raw material gas comprising TEOS.
 27. The methodaccording to claim 5 wherein the crystallization of said semiconductorfilm is carried out by heating.
 28. The method according to claim 5wherein said semiconductor device is an active matrix display device.29. The method according to claim 6 wherein said semiconductor film isformed by LPCVD.
 30. The method according to claim 6 wherein said firstinsulating film and said second insulating film are formed by PCVD usinga raw material gas comprising TEOS.
 31. The method according to claim 6wherein the crystallization of said semiconductor film is carried out byheating.
 32. The method according to claim 6 wherein said semiconductordevice is an active matrix display device.
 33. The method according toclaim 7 wherein said semiconductor film is formed by LPCVD.
 34. Themethod according to claim 7 wherein said second insulating film and saidthird insulating film are formed by PCVD using a raw material gascomprising TEOS.
 35. The method according to claim 7 wherein thecrystallization of said semiconductor film is carried out by heating.36. The method according to claim 7 wherein said semiconductor device isan active matrix display device.
 37. The method according to claim 8wherein said semiconductor film is formed by LPCVD.
 38. The methodaccording to claim 8 wherein said second insulating film and said thirdinsulating film are formed by PCVD using a raw material gas comprisingTEOS.
 39. The method according to claim 8 wherein the crystallization ofsaid semiconductor film is carried out by heating.
 40. The methodaccording to claim 8 wherein said semiconductor device is an activematrix display device.